1. Field of the Invention
This invention relates to a display device for displaying the film speed of a film used and the upper limit object distance over which flash light emitted by a flash device reaches effectively (hereinafter referred to as the effective flash distance).
2. Description of the Prior Art
The effective flash distance of a flash device is varied by the film speed of a film used, but the user has often been liable to forget this fact and fail in photographing. For example, when a film of high film speed is replaced with a film or low film speed, the effective flash distance is decreased, but the user has sometimes effected photography at an object distance exceeding the effective flash distance while forgetting this fact and thus, the resultant photograph has become under-exposed.
Accordingly, a flash device which displays the effective flash distance as disclosed in U.S. Pat. No. 4,494,851 has been devised.